Nobody knows exactly what the sequence of events will be, but it is becoming increasingly clear that our way of life will take a drastic downward turn in the next 50 years or less. Environmental destruction is out of control, with the acidification of the oceans and climate change set to be the central engines of our collapse, with the end of cheap energy playing a strong supporting role.
There is no type of leadership that will lead us out of this mess. Far too many people are incapable of accepting the facts, many because of their religious faith, others out of denial, and still others out of inertia. There may be many in positions of wealth and power who simply don't care, because they figure they will be dead by the time things get really bad.
It's possible that some kind of worldwide pandemic will reduce our population and disrupt our economies to a point where we will actually reduce both our energy consumption and our production of greenhouse gases and other pollutants sufficiently to avoid the tipping point that will cause runaway climate change. This disaster that could save our species must happen within the next 10 or 15 years.
I project my own lifespan at another 25 years, maximum. So I may get to see enough of what happens to project the type of planet my immediate descendents will live on.